Human children learn a great deal from their interactions with social partners, including language, cultural norms, and artifact use among other relevant social cognitive abilities. Learning from others requires at least two kinds of abilities in the learner - the ability to represent others' actions as intentional and the ability o use this knowledge very quickly in real time. In the first year of life, converging evidence from passive experimental methods suggests that preverbal infants have an understanding of others' intentions and goals (Guajardo & Woodward, 2004; Woodward, 1998, 1999); however, these same infants may not appear as sophisticated in their knowledge of others during naturalistic interactions that require fast responses. Between 12 and 24 months of age, infants show increasing skill in fine-grained social interactive abilities (social competence), which is a development supported by empirical evidence from naturalistic social interactions (Bakeman & Adamson, 1984; Buttelmann, Carpenter, & Tomasello, 2009). One possibility is that this difference in social competence between years 1 and 2 is not driven primarily by infants' knowledge of the intentions of others; rather, it is that infants become more adept at recruiting this knowledge quickly (Goal Prediction Speed) during social interactions to produce appropriate responses to others. The current proposal will examine how skilled 18-month-old infants are at integrating social knowledge about others (social competence) and whether their speed in responding (Goal Prediction Speed) aids in their development of social skills that are evident in the second year of life. Infants' social competence will be measured with a series of tasks designed to elicit the following behaviors: helping; sharing; joint attention; perspective-taking; and general cognitive ability. Their performance on these tasks will be correlated with a Goal Prediction Speed measure that has been developed within our lab. In this measure, infants' ability to rapidly recruit information about a past event to predict a person's future behavior, as measured through their latency to launch a goal-based predictive fixation, will be examined in an anticipatory looking paradigm using a T60 XL Tobii eye-tracking system. Thus, this proposal will provide a novel measure of social competence by correlating infants' speed when generating goal-based predictions with their performance on social competence measures. Consistent with NICHD's mission of ensuring that all children have the opportunity to achieve their full potential for healthy and productive lives, the current project will shed light on infans' developing social competence, a multidimensional ability that encompasses social, cognitive, and behavioral skills that allow infants to effectively navigate their social world.